SECT. 6.] Origin, or Process of Causation of the Series. 59 



of being developed out of pre-existing forms, it would still 

 be true that amongst the numbers of each that now present 

 themselves the characteristic differences and resemblances 

 are the result of what we have termed agencies. Take, for 

 instance, a single characteristic only, say the height; what 

 determines this as we find it in any given group of men? 

 Partly, no doubt, the nature of their own food, clothing, 

 employment, and so on, especially in the earliest years of 

 their life; partly also, very likely, similar conditions and 

 circumstances on the part of their parents at one time or 

 another. No one, I presume, in the present state of know 

 ledge, would attempt to enumerate the remaining causes, 

 or even to give any indication of their exact nature; but 

 at the same time few would entertain any doubt that 

 agencies of this general description have been the determin 

 ing causes at work. 



If it be asked again, Into what may these agencies 

 themselves be ultimately analysed ? the answer to this 

 question, in so far as it involves any detailed examination 

 of them, would be foreign to the plan of this essay. In so 

 far as any general remarks, applicable to nearly all classes 

 alike of such agencies, are called for, we are led back to 

 the point from which we started in the previous chapter, 

 when we were discussing whether there is necessarily one 

 fixed law according to which all our series are formed. We 

 there saw that every event might be regarded as being 

 brought about by a comparatively few important causes, of 

 the kind which comprises all of which ordinary observation 

 takes any notice, and an indefinitely numerous group of 

 small causes, too numerous, minute, and uncertain in their 

 action for us to be able to estimate them or indeed to take 

 them individually into account at all. The important ones, 

 it is true, may also in turn be themselves conceived to be 



